Gray Screen Test
Use a neutral gray surface to visually inspect display uniformity.
Before you start
Choose a gray level, then inspect the surface from your normal viewing position. Compare all three levels for bands, patches, or tint differences using normal brightness.
Next / Previous or arrow keys change color. Tap or click the plain surface for the next color. Hide controls for a clear view; tap to recover them, or press H or Tab. Exit with the Exit button or Escape.
How to use this test
- Choose a starting gray and view it at normal brightness from your usual position.
- Compare dark, mid, and light gray manually for bands, tint shifts, or broad patches.
- Exit the pattern and check whether the same shading is noticeable in ordinary content.
Want to compare this with timing, colors, and motion in one session? Run the Complete Monitor Test.
What to look for
Gray can make subtle uneven shading more visible than black or white. Dark gray is useful for noticing near-dark OLED bands; mid and light gray can reveal broad patches or a mottled appearance often called dirty-screen effect. These are visual observations rather than measured results.
Know the limitations
The defined gray levels are CSS RGB values, not percentages of panel luminance. Gamma, HDR, brightness settings, viewing angle, and panel processing affect what you see. This page does not calibrate gamma, measure uniformity, or assign a quality score.
If a band is visible only on gray
Record which gray level reveals it and whether it affects normal use. Viewing angle, HDR, gamma, and panel processing can change a subtle pattern. The CSS values are not measured luminance percentages, and a visible band alone does not provide a pass/fail uniformity result.
Common questions
Are these gray levels luminance percentages?
No. Dark, mid, and light gray use RGB values 32, 128, and 192 per channel. The relationship between these values and emitted light depends on your display and its processing.
Does visible banding prove the panel is defective?
No. Compare it with ordinary content and your manufacturer’s guidance. Settings, viewing conditions, and panel behavior can make subtle bands more or less apparent.